1. Field of the Invention
The present invention relates to a method of partially thermally condensing an expandable silicone resin, and in particular, it relates to a process for modifying a commercial silicone resin so that cellular expansion is substantially uniform and controlled, with no large voids or overexpanded pores (.gtoreq.1 mm) formed.
2. Description of the Prior Art
Cellular expansion of silicone resins is described in the Weyer U.S. Pat. No. 2,803,606. A silicone resin is melted and filler, foaming agent and catalyst are added. The molten mixture is allowed to solidify and is then powdered by crushing. The crushed mix is poured into a mold and heated above the decomposition temperature of the blowing agent. The foamed resin is then cured at a temperature above the decomposition temperature.